fix clip: frame for band scales

[mbostock]

Fixes #1202. The previous fix in #950 was only partly correct: in essence, it was trying to undo transform applied by applyTransform:

plot/src/style.js

Lines 383 to 389 in c095660

	export function applyTransform(selection, mark, {x, y}, tx = offset, ty = offset) {
	tx += mark.dx;
	ty += mark.dy;
	if (x?.bandwidth) tx += x.bandwidth() / 2;
	if (y?.bandwidth) ty += y.bandwidth() / 2;
	if (tx || ty) selection.attr("transform", `translate(${tx},${ty})`);
	}

But the behavior of applyTransform varies from mark to mark, and even within a mark depending on which channels are applied, for example for collapsed rects:

plot/src/marks/rect.js

Line 62 in c095660

.call(applyTransform, this, {x: X1 && X2 && x, y: Y1 && Y2 && y}, 0, 0)

Rather than trying to undo the transform, this fix instead wraps the G element with another (untransformed) G element, applying the clip to the parent G element. And thus the clipped region is not affected by the mark’s transform.

To simplify the adoption of this fix, applyIndirectStyles now mutates the passed-in selection.node to return the parent G element when clipping is applied. This means that callers effectively get the fix “for free” (and we now don’t even need to pass scales to applyIndirectStyles). I’m sure there’s a cleaner way to do this, but this seems good for now and minimizes churn.

Previously #949.